Portions of southwestern Ontario could be getting drenched Monday night and Tuesday morning.
Environment Canada has issued a severe thunderstorm watch for Chatham-Kent, Sarnia-Lambton, and southern Huron and Perth counties.
As of 9 p.m. Monday, the weather agency said conditions were favourable for the development of thunderstorms that may bring heavy downpours, frequent lightning, and toonie-sized hail.
"Heavy rain can cause flash flooding and significant reductions to visibility," read the notice from Environment Canada. "Severe thunderstorm watches are issued when conditions are favourable for the development of thunderstorms capable of producing damaging hail, wind, or rain."